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Posted: **Sun Apr 03, 2005 12:00 am**

Hi!
I'm currently developing a small OS. But I have some questions towards the boot sequence:
Grub (0.9.6) is installed in the MBR of the Harddisk (512 Byte - Stage 1) than grub loads Stage 2 which is located at a fixed address (specified in stage1.h), but how is this location linked to an inode and marked as used (e.g. in the ext2/3 bitmap)? And doesn't it conflict with the file system? And how can I instruct grub to load a file from a not specified location which is maybe splited without updating it every time the location changes?
Maybe there are some documents which include the answers to my questions and some additional information.

Thanks
matott

Posted: **Sun Apr 03, 2005 12:00 am**

First you copy stage2 to the filesystem - then it is a normal file in the filesystem. Then you install grub stage 1 on it, which will then be able to load stage2.

and if you don't want to enter everything every time, use a menu.lst file!

Posted: **Sun Apr 03, 2005 12:00 am**

But how does stage1 know where stage2 is on the harddisk (you don't update grub everytime like lilo)?

Code: Select all

  
  File: `/boot/grub/stage1'
  Size: 512             Blocks: 2          IO Block: 4096   regular file
Device: 301h/769d       Inode: 2018        Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2004-07-16 22:01:44.000000000 +0200
Modify: 2004-07-16 22:01:44.000000000 +0200
Change: 2005-01-25 18:13:15.000000000 +0100

  File: `/boot/grub/stage2'
  Size: 100306          Blocks: 198        IO Block: 4096   regular file
Device: 301h/769d       Inode: 2019        Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2005-04-03 17:26:01.000000000 +0200
Modify: 2004-07-16 22:01:44.000000000 +0200
Change: 2005-01-25 18:13:15.000000000 +0100

Posted: **Mon Apr 04, 2005 11:00 pm**

when you install the stage1 in the MBR it stores stage2 inode addresse so she can know the size and all information needed to load stage2.

Posted: **Mon Apr 04, 2005 11:00 pm**

Stage1 would get updated like Lilo if you modify Stage2! Stage2 can load the kernel however without being modified!

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